JP2010192784A - Wiring substrate, probe card, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability wiring substrate with reduced possibility of wire fracture, even if a thermal stress is generated between an insulating resin layer and a ceramic wiring substrate. <P>SOLUTION: This wiring substrate includes a ceramic wiring substrate 1, a plurality of insulating resin layers 2 laminated on the upper surface of the ceramic wiring substrate 1, a plurality of wiring layers 3 on the upper surface of the respective insulating resin layers 2, via conductors 4 that connects the wiring layers 3, 3 disposed on the upper side and lower side of the insulating resin layer 2, and a through conductor 6 that reaches from the upper surface of the lowest layer of the insulating resin layer 2 to the inside of the ceramic wiring substrate 1 and connects the wiring layer 3 of the upper surface of the lowest layer of the insulating resin layer 2 with an external wiring 7a of the upper surface of the ceramic wiring substrate 1. Since there is no connection portion between the end surface of the via conductor 4 with a comparatively weak connecting strength and the external wiring 7a in the interface between the ceramic wiring substrate 1 and the lowest layer of the insulating resin layer 2, whose thermal stress tends to increase, the possibility of wire fracture is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wiring board used for a probe card or a wiring board for mounting electronic components such as a semiconductor element and a piezoelectric vibrator, and a probe card and an electronic apparatus using such a wiring board.

  In recent years, along with miniaturization and higher density of electronic devices, not only semiconductor elements used in electronic devices but also packages, wiring boards on which the semiconductor elements are mounted, or electrical inspection of semiconductor elements The probe card is also required to have finer wiring and higher density. In addition, it is required that a high-frequency signal can be transmitted with an increase in the speed of the semiconductor element, and the probe card is also required to have excellent flatness.

  In order to meet these requirements, fine patterning is possible, and as a substrate with excellent flatness and high frequency characteristics, a thin film conductor and a thin insulating layer are formed on a ceramic substrate flattened by polishing. There is a so-called build-up type wiring board in which the formed multilayer wiring portion is formed (see, for example, Patent Document 1). FIG. 6 is a cross-sectional view showing an example of a conventional wiring board. The conventional wiring board is formed by alternately laminating insulating resin layers 12 and wiring layers 13 on the upper surface of a ceramic wiring board 11 composed of a plurality of ceramic insulating layers 18, internal wirings 15 and external wirings 17. The wiring layers 13 positioned above and below the insulating resin layer 12, and the wiring layer 13 on the upper surface of the lowermost insulating resin layer 12 and the external wiring 17a on the upper surface of the ceramic wiring substrate 11 are connected by via conductors 14. It was a thing.

Japanese Patent Laid-Open No. 2004-214586

  However, the conventional wiring board has a thermal expansion coefficient of the insulating resin layer 12 at the connection portion between the via conductor 14 formed in the lowermost insulating resin layer 12 and the external wiring 17a formed on the upper surface of the ceramic wiring board 11. Thermal stress due to the difference in thermal expansion coefficient between the ceramic wiring board 11 and the ceramic wiring board 11 was easily applied. This is because the external wiring 17a on the upper surface of the ceramic wiring board 11 is thin and the bonding strength between the ceramic wiring board 11 and the ceramic insulating layer 18 is higher than that of the insulating resin layer 12. Since the behavior according to the behavior of the wiring substrate 11 (ceramic insulating layer 18) is shown and the via conductor 14 is formed in the insulating resin layer 12, the behavior according to the behavior of the insulating resin layer 12 is shown. The position of the bonding interface between the via conductor 14 formed in the insulating resin layer 12 and the external wiring 17a formed on the upper surface of the ceramic wiring board 11 is caused by the thermal stress between the ceramic wiring board 11 and the insulating resin layer 12 This is because it substantially coincides with the position where it increases.

  With respect to such a conventional wiring board, further miniaturization of the wiring layer 13 is required, and the connection portion of the via conductor 14 with the external wiring 17a on the upper surface of the ceramic wiring board 11 is small, for example, about 50 μm or less in diameter. Then, the connection strength between the via conductor 14 and the external wiring 17a formed on the upper surface of the ceramic wiring board 11 is reduced. In addition, the electrical inspection of semiconductor elements is performed simultaneously with a probe card on a large number of semiconductor elements on the wafer. However, if the size of the wafer increases to reduce the cost of the semiconductor elements, the probe card must also be enlarged. When the wiring board for the probe card becomes large, the thermal stress applied to the connection portion with the external wiring 17a on the upper surface of the ceramic wiring board 11 of the via conductor 14 becomes large. Therefore, there has been a problem that it is easy to break between the via conductor 14 of the lowermost insulating resin layer 12 and the external wiring 17a on the upper surface of the ceramic wiring board 11.

  The present invention has been made to solve the above-described problems, and the purpose of the present invention is to increase the possibility of the wiring breaking even if thermal stress is generated between the insulating resin layer 12 and the ceramic wiring board 11. An object is to provide a reduced and highly reliable wiring board.

  The wiring board of the present invention includes a ceramic wiring board, a plurality of insulating resin layers laminated on the upper surface of the ceramic wiring board, a wiring layer on the upper surface of each of the plurality of insulating resin layers, and above and below the insulating resin layer. Via conductors connecting between the wiring layers positioned, and reaching the upper surface of the lowermost insulating resin layer from within the ceramic wiring substrate, and the wiring layers on the upper surface of the insulating wiring layer of the ceramic wiring substrate and the lowermost insulating resin layer And a through conductor that connects the two to each other.

  In the above configuration, the wiring board of the present invention is characterized in that the through conductor protrudes from the upper surface of the lowermost insulating resin layer into the wiring layer on the upper surface of the lowermost insulating resin layer. .

  The probe card of the present invention comprises the wiring board of the present invention having the above-described configuration and probe pins connected to the wiring layer on the upper surface of the uppermost insulating resin layer.

  An electronic device of the present invention includes the wiring board of the present invention having the above-described configuration and an electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer.

  According to the wiring board of the present invention, the penetration extends from the upper surface of the lowermost insulating resin layer into the ceramic wiring board and connects the wiring layer on the upper surface of the lowermost insulating resin layer and the external wiring on the upper surface of the ceramic wiring board. Since it has a conductor, the interface between the ceramic wiring board and the lowermost insulating resin layer where the thermal stress is increased does not have a connection portion between the end face of the via conductor having relatively low connection strength and the external wiring, Since the through conductor is hardly sheared by thermal stress, it becomes a highly reliable wiring board in which the possibility that the wiring breaks is reduced.

  According to the wiring substrate of the present invention, in the above configuration, when the through conductor protrudes from the upper surface of the lowermost insulating resin layer into the wiring layer on the upper surface of the lowermost insulating resin layer, the insulating resin layer and the ceramic wiring substrate Acts in a direction parallel to the connection interface between the through conductor and the upper wiring layer of the lowermost insulating resin layer at the connection portion between the through conductor closest to the interface with the upper wiring layer of the lowermost insulating resin layer Since the connection area between the through conductor and the wiring layer on the upper surface of the lowermost insulating resin layer is large against thermal stress, the side of the protruding part of the through conductor is also subjected to stress. This results in a high connection strength and a highly reliable wiring board in which the possibility of the wiring breaking is further reduced.

  According to the probe card of the present invention, the wiring board of the present invention having the above-described configuration and the probe pin connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided. Even if it is a thing, it becomes a highly reliable probe card by which possibility that the wiring will fracture | rupture by a temperature change was reduced.

  According to the electronic device of the present invention, since the wiring board of the present invention having the above configuration and the electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided, the wiring breaks due to a temperature change. Therefore, it is possible to obtain a smaller and more reliable electronic device on which a smaller electronic component such as a semiconductor element with fine wiring is mounted.

It is sectional drawing which shows an example of embodiment of the wiring board of this invention. It is sectional drawing which expands and shows the A section of FIG. It is sectional drawing which expands and shows the principal part of the other example of the wiring board of this invention. It is sectional drawing which expands and shows the principal part of the other example of the wiring board of this invention. It is sectional drawing which expands and shows the principal part of the other example of the wiring board of this invention. It is sectional drawing which shows an example of the conventional wiring board.

  A wiring board of the present invention, a probe card using the wiring board, and an electronic device will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment of a wiring board according to the present invention. FIG. 2 is an enlarged cross-sectional view showing a portion A of FIG. 3 to 5 are cross-sectional views showing, in an enlarged manner, main portions of other examples of the wiring board of the present invention similar to FIG. 1 to 5, 1 is a ceramic wiring board, 2 is an insulating resin layer, 3 is a wiring layer formed on the insulating resin layer 2, 4 is a via conductor formed through the insulating resin layer 2, 5 is an internal wiring of the ceramic wiring board 1, 6 is a through conductor, 7 is an external wiring on the surface of the ceramic wiring board 1, 7a is an external wiring on the upper surface of the ceramic wiring board 1, and 8 is a ceramic insulating layer of the ceramic wiring board 1. is there. In the example shown in FIG. 1, the wiring board 3 on the outermost surface of the wiring board has four wiring layers, the insulating resin layer 2 has two layers, and the ceramic insulating layer 8 of the ceramic wiring board 1 has three layers. . Depending on the number of terminals of electronic components mounted on the wiring board, the number of semiconductor elements on the wafer to be inspected by the probe card, the number of terminals of the semiconductor elements, and their arrangement, the insulating resin layer 2, the wiring layer 3, The size and arrangement of the via conductor 4, the internal wiring 5, the through conductor 6, and the external wiring 7 are set.

  The wiring board of the present invention includes a ceramic wiring board 1, a plurality of insulating resin layers 2 laminated on the upper surface of the ceramic wiring board 1, and a plurality of insulating resin layers 2, as in the examples shown in FIGS. The upper wiring layer 3, the via conductors 4 connecting the wiring layers 3 and 3 positioned above and below the insulating resin layer 2, and the lowermost insulating resin layer 2 from the upper surface into the ceramic wiring substrate 1, A through conductor 6 for connecting the wiring layer 3 on the upper surface of the lower insulating resin layer 2 and the external wiring 7a on the upper surface of the ceramic wiring substrate 1 is provided. Because of such a configuration, a connection portion between the end face of the via conductor 4 having a relatively low connection strength and the external wiring 7a is formed at the interface between the ceramic wiring substrate 1 and the lowermost insulating resin layer 2 where thermal stress increases. Since the through conductors 6 are not easily broken by thermal stress, the wiring conductor 6 is a highly reliable wiring board that is less likely to break the wiring. 1 to 5, the through conductor 6 is connected to the internal wiring 5 of the ceramic wiring board 1 through the external wiring 7a on the upper surface of the ceramic wiring board 1, so that the through conductor 6 and the depth of the portion embedded in the ceramic wiring board 1 can be determined without considering the size and arrangement of the internal wiring 5 of the ceramic wiring board 1. Become.

  Further, as in the example shown in FIG. 3, in the wiring board of the present invention, in the above configuration, the through conductor 6 is a wiring layer located on the upper surface of the lowermost insulating resin layer 2 from the upper surface of the lowermost insulating resin layer 2. It is preferable that it protrudes into 3. In such a configuration, the through conductor 6 is connected to the through conductor 6 closest to the interface between the insulating resin layer 2 and the ceramic wiring substrate 1 and the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2. The connection area between the through conductor 6 and the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2 against thermal stress acting in a direction parallel to the connection interface with the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2 Since the structure is large and the side surface of the protruding portion of the through conductor 6 is also subjected to stress, the connection strength of the connection portion is high, and the possibility that the wiring breaks is further reduced. Wiring board.

  The probe card of the present invention comprises the wiring board of the present invention configured as described above and probe pins connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. As a result, even a large card corresponding to a large wafer is a highly reliable probe card in which the possibility that the wiring breaks due to a temperature change is reduced.

  An electronic device according to the present invention includes the above-configured wiring board according to the present invention and an electronic component connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. . As a result, even a large card corresponding to a large wafer is a highly reliable probe card in which the possibility that the wiring breaks due to a temperature change is reduced.

  The ceramic wiring board 1 has an insulating base made of ceramics, external wirings 7 and 7a formed on the surface thereof, and internal wiring 5 formed inside. As shown in the examples shown in FIGS. 1 to 5, the insulating base is composed of a plurality of ceramic insulating layers 8, and by expanding the internal wiring 5, the interval between the external wirings 7 on the lower surface of the ceramic wiring substrate 1 can be increased. . When the interval between the wiring layers 3 on the upper surface of the insulating resin layer 2 is large, it is not necessary to develop the internal wiring 5, so the ceramic insulating layer 8 may be composed of one layer. The external wiring 7 on the lower surface of the ceramic wiring board 1 is for connecting the wiring board to an external circuit, and the external wiring 7a on the upper surface of the ceramic wiring board 1 is a via conductor 4 formed in the insulating resin layer 2 thereon. In addition, the wiring layer 3 and the through conductor 6 are connected to each other. The internal wiring 5 is used to electrically connect the external wiring 7 on the lower surface of the ceramic wiring substrate 1 and the wiring layer 3 formed on the insulating resin layer 2 via the external wiring 7a on the upper surface of the ceramic wiring substrate 1. There are an internal wiring layer between the ceramic insulating layers 8 and 8 and an internal through conductor that passes through the ceramic insulating layer 8 and connects the internal wiring layer and the internal wiring layer and the external wiring 7.

The ceramic insulating layer 8 of the ceramic wiring substrate 1 includes an aluminum oxide (alumina: Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, a silicon carbide (SiC) sintered body, and a mullite sintered body. Body and ceramics such as glass ceramics. When used for a probe card, an aluminum oxide (Al ₂ O ₃ ) sintered material or glass ceramics having a thermal expansion coefficient close to that of silicon (Si) forming a wafer is preferable. When the ceramic insulating layer 8 is made of such ceramics, when the probe terminal is formed on the wiring board, the wafer and the wiring board joined together with the probe terminal, which are added to the probe terminal and the joint portion of the probe terminal, This is preferable because the thermal stress due to the difference in thermal expansion is relatively small. Further, when used as a probe card, it is possible to effectively prevent thermal deformation with respect to a thermal load during measurement of the electrical characteristics of the semiconductor element, and furthermore, heat is not retained inside due to high heat transfer properties.

  The internal wiring 5 and the external wirings 7 and 7a of the ceramic wiring substrate 1 are formed by simultaneous firing with the ceramic insulating layer 8, and tungsten (W), molybdenum (Mo), molybdenum-manganese (Mo-Mn) alloy, silver ( Ag), copper (Cu), gold (Au), silver-palladium (Pd) alloy and the like, which is made of metallization mainly composed of metal.

  Such a ceramic wiring substrate 1 is manufactured by the following method. For example, when the ceramic insulating layer 8 is formed of an aluminum oxide sintered body, first, an appropriate organic binder and solvent are added to and mixed with raw material powders of aluminum oxide, silicon oxide, magnesium oxide and calcium oxide, and the slurry is mixed. This is formed into a sheet shape by a doctor blade method or the like to produce a plurality of ceramic green sheets to be the ceramic insulating layer 8.

  Next, a through hole is formed by a suitable punching process at a predetermined position where the internal through conductor of the ceramic green sheet is formed, and the through hole is filled with a conductive paste. Further, a conductor paste layer serving as an internal wiring layer is formed to a thickness of 10 to 20 μm at a predetermined position of the ceramic green sheet by screen printing or the like. The conductive paste is produced by kneading a metal powder having a high melting point such as tungsten (W), molybdenum (Mo), molybdenum-manganese (Mo-Mn) alloy, an appropriate resin binder, and a solvent.

  Finally, these ceramic green sheets are superposed and pressure-bonded to produce a laminate, and the laminate is fired at a high temperature of about 1500 ° C. to 1600 ° C., thereby producing the ceramic wiring substrate 1. On the surface of the external wiring 7 and 7a of the ceramic wiring board 1, a nickel plating layer with a thickness of about 1 to 10 μm and a gold plating layer with a thickness of about 0.1 to 3 μm are provided to prevent corrosion and connect with external circuits. It may be formed sequentially. A similar plating layer may be formed on a portion of the internal wiring 5 (internal through conductor) exposed on the surface of the ceramic wiring substrate 1.

  The external wiring 7a on the upper surface of the ceramic wiring substrate 1 is made by flattening the upper surface of the ceramic wiring substrate 1 having no external wiring 7a by polishing the upper surface, and then metallizing or vapor deposition such as the Moriman method. Alternatively, a thin film forming method such as a sputtering method or an ion plating method may be used. In the case of the metallization method, for example, a metal paste containing a metal powder such as tungsten (W), molybdenum (Mo), manganese (Mn), an appropriate resin binder and solvent at a predetermined position of the ceramic wiring substrate 1 by a screen printing method or the like. And is heat-treated at a high temperature of 1400 ° C. or higher. In the case of the thin film forming method, a base conductor layer made of, for example, a chromium (Cr) -Cu alloy layer or a titanium (Ti) -Cu alloy layer having a thickness of about 0.1 μm to 3 μm is formed on the entire upper surface of the ceramic wiring substrate 1. A resist film having a pattern-shaped opening of the external wiring 7a is formed thereon, and a main conductor having a thickness of about 2 μm to 10 μm made of a metal such as copper or gold by plating or the like using the resist film as a mask. Form a layer. Then, the resist film is peeled and removed, and the exposed portion of the underlying conductor layer is removed by etching, whereby the external wiring 7a is formed. A nickel or gold plating layer may be further formed on the surface by plating.

  The insulating resin layer 2 is made of an insulating resin such as polyimide resin, polyphenylene sulfide resin, wholly aromatic polyester resin, BCB (benzocyclobutene) resin, epoxy resin, bismaleimide triazine resin, polyphenylene ether resin, polyquinoline resin, or fluororesin. It consists of

  In order to form the insulating resin layer 2 on the ceramic wiring substrate 1, for example, when it is made of polyimide resin, a varnish-like polyimide precursor is applied to the upper surface of the substrate 1 by spin coating, die coating, curtain coating, The film is applied by a coating method such as a printing method, and then cured by heat at about 400 ° C. to form a polyimide, thereby forming a thickness of about 10 μm to 50 μm. Alternatively, a resin adhesive such as a siloxane-modified polyamideimide resin, a siloxane-modified polyimide resin, a polyimide resin, a bismaleimide triazine resin, or an epoxy resin is dried on the lower surface of a sheet of about 10 μm to 50 μm made of the above resin with a dry thickness of about 5 to 20 μm An adhesive layer is formed by applying and drying by a coating method such as a doctor blade method, and the adhesive layer is formed on the ceramic wiring substrate 1 by heating and pressing. In any method, the plurality of insulating resin layers 2 are formed by forming the via conductors 4 and the wiring layers 3 in the insulating resin layer 2 and repeating the above steps as many times as the number of necessary insulating resin layers 2. In the method using a resin for a film, a plurality of films can be pressed at once, and it is not necessary to apply and cure for each layer, so that the manufacturing process can be shortened.

Since the via conductor 4 is formed in the insulating resin layer 2, for example, a through hole having a diameter of 20 μm to 100 μm is formed in this portion. This through hole is formed by first forming a resist film having an opening in the insulating resin layer 2 and etching the insulating resin layer 2 located in the opening of the resist film, or directly using a laser. It is formed by removing a part of. As the laser at this time, an excimer laser, a CO ₂ laser, or the like can be used. However, the shape of the inner wall of the through hole can be adjusted almost vertically, and the inner wall surface of the through hole can be formed with an ultraviolet laser that can be processed smoothly. Is desirable. Alternatively, in the case of a method of applying a varnish-like resin, a photosensitive resin is used, for example, a portion other than a portion where a through-hole is formed by exposure is cured, and a resin in a portion where the through-hole is formed is obtained. The through hole may be formed by removing by etching.

  First, the wiring layer 3 is formed by, for example, chromium (Cr) having a thickness of about 0.1 μm to 3 μm on the entire main surface of the insulating resin layer 2 by a thin film forming method such as vapor deposition, sputtering, or ion plating. ) A base conductor layer made of a -Cu alloy layer or a titanium (Ti) -Cu alloy layer is formed. Next, a resist film having a pattern-shaped opening of the wiring layer 3 is formed on the underlying conductor layer, and the resist film is used as a mask to form a metal having a low electrical resistance such as copper or gold by plating or the like. A main conductor layer having a thickness of about 10 μm is formed. Then, the wiring layer 3 is formed by removing the resist film and removing the exposed portion of the underlying conductor layer by etching. Similar to the external wiring 7, a nickel or gold plating layer may be formed on the surface of the uppermost wiring layer 3 by plating.

  As shown in the example shown in FIG. 4, when the wiring layer 3 is formed with a recess having the same shape as the wiring layer 3 in the insulating resin layer 2 and the wiring layer 3 is formed in the recess, the upper surface of the insulating resin layer 2 is formed. Since there is no step between the wiring layer 3 and the upper surface of the wiring layer 3, the upper surface of the wiring substrate is flat even if a plurality of insulating resin layers 2 are stacked, and the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. It is preferable because an electronic component and a probe pin can be connected better. In order to form a recess in the insulating resin layer 2, a resist film having a pattern-shaped opening of the wiring layer 3 is formed on the surface of the insulating resin layer 2, and the insulating resin layer is etched by an etching method such as RIE (Reactive Ion Etching). The surface of the exposed portion of 2 may be removed.

  When the through conductor 6 protrudes from the upper surface of the lowermost insulating resin layer 2 into the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2, the through conductor 6 protrudes from the upper surface of the lowermost insulating resin layer 2. And the wiring layer 3 may be formed by the above-described method so as to overlap therewith. In the example shown in FIG. 3, the wiring layer 3 is also formed and connected to the upper surface of the through conductor 6, but the side surface of the through conductor 6 and the wiring layer 3 are connected through the wiring layer 3. It may be.

  Before forming the wiring layer 3, the via conductor 4 is formed by filling a through hole of the insulating resin layer 2 with a conductive paste mainly composed of metal powder such as copper and resin, as shown in FIGS. As shown in the example shown in FIG. 5, a through hole filled with a conductor is formed. The conductor paste is made of a metal powder such as copper, a resin, and a solvent, and is solidified by filling the through holes and then drying. Alternatively, when the wiring layer 3 is formed, it may be formed simultaneously with the wiring layer 3 by forming the base conductor layer and the main conductor layer on the inner surface of the through hole. In this case, the via conductor 4 is formed by being attached to the inner surface of the through hole of the insulating resin layer 2, and the through hole is not filled with the conductor. When the plating thickness at the time of forming the main conductor layer is increased, the through-holes can be filled with the conductor as in the examples shown in FIGS. When the via conductor 4 is formed at the same time as the wiring layer 3, the through hole is formed as shown in the example shown in FIGS. 1 to 5 so that the base conductor layer can be satisfactorily formed by a thin film on the inner surface of the through hole. It is preferable to make the shape so that the upper surface side of the insulating resin layer 2 becomes larger. The through hole having such a shape is controlled by etching conditions when the through hole is formed by etching, by adjusting the output of the laser when the through hole is formed by a laser, or by exposure condition or etching when using a photosensitive resin. It can be formed depending on conditions.

  The through conductor 6 extends from the upper surface of the lowermost insulating resin layer 2 into the ceramic wiring substrate 1, or further from the upper surface of the lowermost insulating resin layer 2 to the upper wiring layer 3 of the lowermost insulating resin layer 2. The via conductor 4 of the lowermost insulating resin layer 2 may extend into the ceramic wiring substrate 1 and is formed by simultaneous firing with the ceramic wiring substrate 1 and is ceramic. It may protrude from the uppermost ceramic insulating layer 8 of the wiring board 1.

  When the through conductor 6 is one in which the via conductor 4 of the lowermost insulating resin layer 2 extends into the ceramic wiring substrate 1, it can be formed as follows. First, the ceramic wiring board 1 having a hole into which the lower portion of the through conductor 6 enters is prepared on the upper surface. After the ceramic wiring substrate 1 is manufactured as described above, holes may be formed by laser processing or blast processing using a mask, or a ceramic green sheet that becomes the laminated body before firing or the uppermost ceramic insulating layer 8 A hole may be formed by laser processing or the like. The ceramic wiring board 1 manufactured as described above is, for example, as shown in FIGS. Alternatively, the ceramic wiring substrate 1 may be manufactured by forming a through hole to be a hole in a ceramic green sheet to be the uppermost ceramic insulating layer 8. The ceramic wiring board 1 produced in this way is as shown in the example shown in FIG. Next, the insulating resin layer 2 is formed on the ceramic wiring substrate 1 having the holes to form through holes. Then, the through conductor 6 is formed by the method of forming the via conductor 4 described above. When the through conductor 6 is projected from the upper surface of the lowermost insulating resin layer 2 into the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2, if necessary, the periphery of the through hole of the lowermost insulating resin layer 2 A resist is formed in advance, and the thickness of the plating film to be the through conductor 6 may be increased. At this time, if the plating is electrolytic plating and a plating film such as copper is deposited on the internal wiring 5 using the internal wiring 5 as an electrode, the through conductor 6 that does not contain voids even when the aspect ratio is high. Therefore, it is preferable because the through conductor 6 has high strength, high bonding reliability, and low electrical resistance.

  Alternatively, as in the case of the via conductor 4, for example, a conductive paste mainly composed of a metal powder such as copper and a resin is filled in the through holes of the insulating resin layer 2 as in the examples shown in FIGS. 1 to 5. In addition, the through conductor 6 in which the through hole is filled with the conductor can be formed.

  When the through conductor 6 is a via conductor 4 of the lowermost insulating resin layer 2 extending into the ceramic wiring substrate 1 and the insulating resin layer 2 is formed by applying a varnish-like resin. Is preferably applied to the periphery of the hole so that a through hole opening in the insulating resin layer 2 above the hole is formed so that the varnish-like resin does not enter the hole on the upper surface of the ceramic wiring substrate 1. In order to prevent the varnish-like resin from flowing into the hole, the diameter of the through hole of the insulating resin layer 2 is made larger than the diameter of the hole on the upper surface of the ceramic wiring board 1 as in the example shown in FIG. It is preferable to apply. However, even if the varnish enters the hole, it can be removed by etching such as laser or RIE. The method of bonding the resin sheet by a hot press is preferable because the resin does not flow into the hole on the upper surface of the ceramic wiring substrate 1.

  When the through conductor 6 is formed by simultaneous firing with the ceramic wiring substrate 1 and protrudes from the uppermost ceramic insulating layer 8 of the ceramic wiring substrate 1, it can be formed as follows. First, the through wiring conductor 6 is formed from the second ceramic insulating layer 8 from the top to the uppermost ceramic insulating layer 8, and the ceramic wiring substrate 1 in which the inner wiring 5 is not formed in the uppermost ceramic insulating layer 8 is manufactured. To do. The upper surface of the wiring ceramic wiring substrate 1 is polished flat, and a resist film is formed on the portion where the through conductor 6 is exposed on the upper surface. Next, the upper surface of the ceramic wiring substrate 1 is ground by sandblasting to grind only the uppermost ceramic insulating layer 8 and then the resist is peeled off so that a part of the through conductor 6 protrudes from the upper surface and the internal wiring 5 The ceramic wiring board 1 with the surface exposed is manufactured.

  Alternatively, an etching method in which the ceramic insulating layer 8 has a higher etching rate than the through conductor 6 may be used. For example, when the ceramic insulating layer 8 is made of glass ceramics and the through conductor 6 is mainly composed of copper, the glass ceramic of the ceramic insulating layer 8 has a processing rate of RIE etching rather than the copper of the through conductor 6. Since it is fast, it is possible to remove the surface of the ceramic insulating layer 8 while leaving the upper part of the through conductor 6 mainly composed of copper in a columnar shape. Even when glass such as ammonium fluoride is easy to dissolve and the metal is difficult to dissolve, the same can be applied.

  Alternatively, when the ceramic wiring board 1 is manufactured, the ceramic paste is sintered by shrinking the conductive paste for the through conductor 6 with a composition having a smaller sintering shrinkage than the ceramic green sheet or at a lower temperature than the ceramic green sheet. By firing using a conductor paste having a composition that does not shrink when shrinking, the ceramic wiring board 1 with the through conductors 6 protruding can be produced. Further, if the ceramic insulating layer 8 is made of glass ceramics, firing is performed by laminating a constrained green sheet mainly composed of alumina or the like on both sides of the laminate, which does not sinter and shrink at the temperature at which the ceramic green sheet is sintered. Then, the ceramic green sheet is restrained from sintering shrinkage in the direction of the laminated surface by the constraining green sheet, and is more likely to shrink in the thickness direction, so that it is easier to project the through conductor 6 and the shrinkage in the planar direction is small. This is preferable because a ceramic wiring board 1 with good shrinkage variation and dimensional accuracy can be obtained.

  In order to form the lowermost insulating resin layer 2 on the upper surface of the ceramic wiring substrate 1 in which a part of the through conductor 6 protrudes from the uppermost ceramic insulating layer 8, for example, the following may be performed. . First, a varnish-like polyimide resin is formed into a semi-cured film in advance, and the polyimide resin is cured by placing it on the ceramic wiring substrate 1 and then heat-pressing. 2 covered. When the insulating resin layer 2 is polished until the through conductor 6 is exposed, the through conductor 6 extends from the ceramic wiring substrate 1 to the upper surface of the lowermost insulating resin layer 2. If the polishing at this time is performed only by mechanical polishing, the through conductor 6 is easily bent by the force during mechanical polishing. Therefore, rough polishing until the thickness of the resin layer such as polyimide resin on the through conductor 6 reaches about 50 μm is performed by mechanical polishing. It is preferable that the polishing is performed, and thereafter, the entire surface of the insulating resin layer 2 is etched and flattened using RIE. In particular, when the insulating resin layer 2 is polished from the upper surface of the lowermost insulating resin layer 2 into the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2, the insulating resin layer 2 is polished until the through conductor 6 is exposed by mechanical polishing. Even then, the entire surface of the insulating resin layer 2 is etched using RIE, thereby preventing the through conductor 6 from being deformed or reducing its diameter, while protruding the through conductor 6 from the upper surface of the lowermost insulating resin layer 2. This is preferable.

  In the case of the manufacturing method and material as described above, if the diameter of the through conductor 6 is about 75 μm to 200 μm, the heat due to the difference between the thermal expansion coefficient of the insulating resin layer 2 and the thermal expansion coefficient of the ceramic wiring board 1 is obtained. The possibility of breakage due to stress is small. At this time, the length from the interface between the lowermost insulating resin layer 2 of the through conductor 6 and the ceramic wiring board 1 to the upper wiring layer 3 of the lowermost insulating resin layer 2 (= the lowermost insulating resin layer) 2) is about 20 μm to 50 μm, and the length from the interface between the insulating resin layer 2 as the lowermost layer of the through conductor 6 and the ceramic wiring board 1 to the lower end located in the ceramic wiring board 1 (= in FIG. 5) In the example shown, if the thickness of the uppermost ceramic insulating layer 8 of the ceramic wiring substrate 1 is about 100 μm to 500 μm, the connecting portion between the through conductor 6 and the wiring layer 3 and the through conductor 6 and the internal wiring 5 are caused by thermal stress. The possibility of breaking at the connecting portion is small.

  The probe card of the present invention comprises the above-described wiring board of the present invention and probe pins connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. The probe pin is produced, for example, as follows and attached to the wiring board of the present invention. First, a female die of a plurality of probe pins is formed on one surface of a silicon wafer by etching, a metal made of nickel is deposited on the surface on which the female die is formed by plating, and the female die is embedded and embedded with nickel. Nickel on the wafer other than nickel is removed by performing a process such as etching to produce a silicon wafer in which nickel probe pins are embedded. Nickel probe pins embedded in the silicon wafer are bonded to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2 of the wiring substrate by a bonding material such as solder. Then, the probe card is obtained by removing the silicon wafer with an aqueous potassium hydroxide solution.

  The electronic device of the present invention includes the above-described wiring board of the present invention and an electronic component connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. The electronic component is, for example, a semiconductor element such as an IC chip or a piezoelectric vibrator such as a crystal vibrator, and a passive element such as a chip capacitor is also mounted as necessary. Such connection of the electronic component to the wiring layer 3 is performed by soldering, bonding with a conductive adhesive, and wire bonding.

1: Ceramic wiring board 2: Insulating resin layer 3: Wiring layer 4: Via conductor 5: Internal wiring 6: Through conductor 7: External wiring 7a: External wiring on the upper surface of the ceramic wiring board 8: Ceramic insulating layer

Claims (4)

Connecting a ceramic wiring substrate, a plurality of insulating resin layers laminated on the upper surface of the ceramic wiring substrate, a wiring layer on each of the plurality of insulating resin layers, and the wiring layers positioned above and below the insulating resin layer A via conductor extending from the upper surface of the lowermost insulating resin layer into the ceramic wiring substrate and connecting the wiring layer on the upper surface of the lowermost insulating resin layer and the external wiring on the upper surface of the ceramic wiring substrate A wiring board comprising a conductor. 2. The wiring board according to claim 1, wherein the through conductor protrudes from the upper surface of the lowermost insulating resin layer into the wiring layer on the upper surface of the lowermost insulating resin layer. A probe card comprising: the wiring board according to claim 1; and a probe pin connected to a wiring layer on an upper surface of the uppermost insulating resin layer. An electronic device comprising: the wiring board according to claim 1; and an electronic component connected to a wiring layer on an upper surface of the uppermost insulating resin layer.

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